Specialized Anatomy of the teeth and age distribution

Question 1

Importance of anatomical knowledge of teeth

Answer 1

-dental surgery
-nerve blocks
-age estimation

Question 2

When did equine dentistry and age estimation begin?

Answer 2

goes back more than 3000 yrs

Question 3

When did horsemen begin aging horses?

Answer 3

-was actively used until early 1900s when record keeping took precedence

Question 4

Purpose of aging horses

Answer 4

-used in legal disputes
-double checking ID
-regulatory inspections
- legal documents and forensic investigations

Question 5

General predisposing dental conditions

Answer 5

-crowded teeth in brachycephalic
-fractured teeth/exposed pulp
-attritions (wear due to bad habits or bad teeth formation)
-retained deciduous

Question 6

Retained deciduous

Answer 6

Adult canine erupts beside and not under the deciduous tooth so it does not cause root resorption
o Upper retained milk canine is usually caudal
o Lower milk is usually lateral to its adult

Question 7

Dental nerve blocks

Answer 7

-local anesthetic deposited near nerve track
-effective, easy, inexpensive, rapid onset
-allows for lighter general anesthesia and complement/lower analgesic in dogs and cats
-better recovery; reduced complications
-main form of anesthesia in ox/horses

Question 8

Maxillary alveolar (of V-2)

Answer 8

-enters maxillary foramen into infraorbital canal
-block for upper teeth, alveolar bone, soft tissue
-remnants exit infraorbital foramen as infraorbital nerve to muzzle

Question 9

Mandibular alveolar (of V-3)

Answer 9

• Enters the mandibular foramen into mandibular canal
• Block for all lower teeth, surrounding bone, soft tissue
• Remnants exit mental foramina as mental nerves to chin

Question 10

Rostral maxillary (infraorbital) nerve block

Answer 10

-target infraorbital foramen and canal
-Dog: foramen above distal root of P^3
-Cat: foramen above mesial root of P^3

Question 11

Depth of canal for rostral maxillary (infraorbital) nerve block

Answer 11

-dolichocephalic and mesanticephalic dogs
>canal is ~2.5cm in large dogs, and with head tilted back, can block as distally as P3
>blocks Incisors and canines, bone, soft tissue, muzzle

-brachycephalic
>canal is ~1cm
>be careful that needle does not enter and cause damage to orbit

-small dogs and cats
> canal ~0.4cm
> blocks all upper teeth

Question 12

Caudal maxillary nerve block target

Answer 12

• Not needed in cats and small dogs
• Target is vicinity of maxillary foramen in pterygopalatine fossa

Question 13

Caudal maxillary nerve block

Answer 13

Blocks maxillary nerve and its branches (infraorbital, pterygopalatine, major and minor palatine) before entering foramen
- Blocks all upper teeth, associated done and soft tissue, palatine mucosa and bone to midline raphe

Question 14

Needle insertion for caudal maxillary nerve block

Answer 14

From oral vestibule, insert needle distal to M2, only ~0.5cm deep in a dorsal direction

Question 15

Rostral mandibular (mental) nerve block target

Answer 15

-target middle mental foramen and mandibular canal

Question 16

Rostral mandibular (mental) nerve block

Answer 16

• Blocks mental nerve and rostral alveolar branches
• Blocks incisor, canine (if deposited caudally in canal even as far back as P3), bone, soft tissue, lower lip

Question 17

Needle insertion for rostral mandibular (mental) nerve block

Answer 17

-Dog: middle mental foramen is apical to medial root of P^2 and 1/3rd way up from ventral border of mandible body
-Cat: foramen is between canine and P3 (lower). Insert the needle rostral to mandibulo-labial frenulum

Question 18

Caudal mandibular (inferior) nerve block target

Answer 18

• Target vicinity of mandibular foramen which is located in medial side of ramus in a fossa
  »Dog: fossa is palpable intra-orally
• located half-way from M3 toward angular process and can be accessed extra-orally or intra-orally

Question 19

Caudal mandibular (inferior) nerve block

Answer 19

-blocks innervation to all lower teeth and associated bone, soft tissue, chin skin

Question 20

What do you need to be careful of when doing a caudal mandibular (inferior) nerve block?

Answer 20

Stay close to the bone to ensure that you don’t block the nearby lingual nerve which would result in self-mutilation

Question 21

Ways to test age estimation of animals

Answer 21

-mostly based on teeth
-time of tooth eruption
(reliable)
- wear on teeth
(unreliable)
-can also use horn rings

Question 22

Cementum annuli

Answer 22

-rather accurate for older ages but less practical
-mostly for forensic of archeological purposes
-based on pattern of rings (annulus) of cement deposit in tooth rot
-dark during less growth (winter), light during growth (spring/summer)

Question 23

First teeth of puppies

Answer 23

• Puppy is toothless at birth
• First teeth erupt at ~3-4 weeks and deciduous set is complete at 6 weeks
• No p1 present in milk set

Question 24

First permanent teeth of puppy

Answer 24

First permanent erupts at ~3months and whole set is complete at 6-7 months

-Occurs earlier in larger breeds than smaller ones

Question 25

General appearance of milk teeth

Answer 25

Resemble adult set but smaller, sharper and have long slender roots